A dynamic imagery task that was designed by Schwartz and Black (1999), henceforth called the
water tilting task, was used for our study. The basic water tilting task involves two drinking glasses
of equal heights but different diameters. Participants are asked to imagine that both glasses would
be filled with water to the same level and to tilt the glasses so that the imagined water would reach
the rim of the glass. Tilting a glass of water is an everyday movement with which even very young
children have a lot of motor experience. On the other hand, we usually do not consciously deliberate
about tilting glasses, and the water tilting task poses a physical/geometrical problem that is not addressed
in general school curricula. Previous results obtained with numerous variations of this basic
task (Schwartz, 1999; Schwartz & Black, 1999) suggest that adults are in fact able to solve the task by
manually tilting the glasses. They correctly tilted thin glasses farther than wide ones, although they
did not seem to have accurate descriptive knowledge about this. Schwartz and Black (1999) concluded